See this gcc bugzilla entry for a discussion I've had about chrono support in the gcc implementation. http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41861 Unfortunately, monotonic_clock support, even if it exists, is a transparent lie. It's not so much a problem with the chrono library as it is a problem with the thread library's use of chrono. A monotonic clock is used to provide somewhat accurate/reliable wait times even in the face of changing clocks, especially in the case of mutexes and condition variables. When condition::wait_until is called with a monotonic_clock time_point, that time_point is translated to a system_clock time_point. If the system_clock is changed (via NTP, adjtime, settimeofday, etc) between when convert_to<system_clock> is called and when the underlying posix call is made, the very reason for using monotonic_clock defenestrates and splatters all over the pavement. Depending on the magnitude of the clock change, wait_until could hang forever. In my opinion, all convert_to calls in the thread library should go to the monotonic_clock, if available. Not system_clock. I couldn't get the gcc people to understand this, so I won't be able to use <chrono> in the standard library sans modification. Maybe boost will get it right? Let me know if I'm missing a subtle point that moots my concerns. Other than that, I think the this library is great. I need it badly. I haven't looked over all the code yet, but what I've seen looks good.